Poblano Potato Salad

INGREDIENTS

• 2 pounds baby red or new potatoes, cut into 1/2 to 1-inch pieces
• 1/4 cup chopped fresh cilantro leaves
• 1/4 cup mayonnaise
• 1 cup chopped scallions (white and pale green parts only)
• Salt and freshly ground black pepper
• 3 ears fresh corn, husks and silks removed
• 2 poblano chiles, charred, peeled, stemmed, seeded, and chopped (see Cook's Note)
• 1/2 cup sour cream